1. Field of the Invention
This invention relates to an apparatus for stopping a sewing machine which facilitates the removal of a thread used for double chain stitches or covering chain stitches (hereinafter referred to as "a stopping apparatus", when applicable).
2. Discussion of the Related Art
Sewing machines such as a lock stitching machine, an overedge stitch machine, and a double chainstitching machine are available in the art. In addition, an over-lock machine is known in the art which selectively forms overedge stitches, double chain stitches and covering chain stitches. A so-called "interlock machine" is also known in the art which is able to form overedge stitches and double chain stitches simultaneously.
With the interlock machine, a free loop can be pulled out. Hence, by cutting the free loop, the fabric can be readily removed from the sewing machine.
On the other hand, a sewing machine which uses more than one sewing needle and only one lower looper thread to form double chain stitches (such as a sewing machine forming a welt seam with no upper decoration: a so-called "single-side covering chain stitching machine"), cannot form a free loop stitch. Hence, with the sewing machine, it is necessary to remove the fabric before a loop is stitched.
However, the conventional sewing machine which uses more than one sewing needle and only one lower looper thread to form a double chain stitches suffers from the following difficulty. After a predetermined sewing operation, such as an overedge stitching operation, the fabric is removed when the needle bar is located near the top dead point. However more than one needle threads are engaged with the lower looper, which greatly resists the removal of the fabric. In this case, at worst the needle threads may be cut off.